Steering arrangement for light motor vehicles



A ril 27, 1926. ,5s2,477

T. LAFITTE STEERING ARRANGEMENT FOR LIGHT MOTOR VEHICLES Filed Sept. 1 '1924 3 Sheets-Sheet April 27, 1926. 1,5s2,477

T. LAFlTTE STEERING ARRANGEMENT FOR LIGHT MOTOR VEHICLES Filed p 15. 1924 3 Sheets-Sheet 2 A ril 27, 1926. 1,5s2,477

. T. LAFITTE STEERING ARRANGEMENT FOR LIGHT MOTOR VEHIGLES Fedse t. 5, 1924 3 Sheets-Sheet 5 Patenta-ad 2 27, 1335:.,

QNTE@ THODORE LAEITTE, OF EARIS, FRANCE srnnnrne ARBANGEMENT ron LIGHT MOTOE VEHICLES.

Application filed September 15, 1924.

To all whom it may concem:

Be it known that T, THODORE LFITTE, a citizen of the Republic of France, and residing at Paris, Seine Department, No. 15 Avenue Pasteur, in the Republic of France, have invented certain new and useful Steer ing Arrangements for Light Motor Vehicles, of which the following is a specification.

The present invention relates to a steering arrangement whereof the speed-reduction box is so constructed as'to provide for a suliicient reduction ratio for a light motor vehicle, by means of an arrangement which is simple, inexpensive, and adapted to eliminate all play in the steering gear. On the other hand, the several elements such as bars, and levers' are connected together by means of fiuidtight universal connectons which do not require the use of pins and are not subject to disengagement when in operation, the same being so constructed that all play will be eliminated.

The appended drawings which are given by way of example represent a Constructional form of steering gear according to the invention.

Fig. 1 is an elevational view of the said steering gear mounted upon a vehicle frame which is diagrammatically represented, partly in section.

Fig; 2 is a corresponding plan view.

Fig. 3 is a front elevational view of the said steering gear, the vehicle frame being shown insection on the line A--A of Fig. 1.

Fg. 4 is a longitudinal section on a larger scale of the speed-reduction box, on the line B-B of* Fig. 5.

Fig. 5 is a plan view of the said box, w th the top cover, the driving shatt', and the disc thereof removed. V

Fig. 6 is' a plan View of the said box, the lower cover and the disc contained therein being removed.

Fgs. 7, 8 and 9 are diagrammatic vews illustrating the operation ot the speed rcduction box.

Figs. 10, 11 and 12 represent various details on a larger scale,`showing:the connecvtions between the several elements.

The steel-ing arrangement conprises a hand wheel 1 keyed to the end of the steerng sha'ft 2 whereof the other end enters the speed- "'eduction box 3 which is Secured to one of the 'side beams of the vehicle frame. The said box, whose Construction and operation will be further described, reduces the speed Serial No. '737,927.

(in a given ratio) of the movement imparted to the hand wheel, and imparts the same to lever 4 actuating a steerng'bar 5; said bar s connected with a coupling lever 6 upon which is also mounted a connecting bar 8 whereof the other end is connected with a second coupling lever 7.

The speed-reduction box 3 comprises two parts or covers, the upper cover 9 and the lower cover 10, Fig. 4; which are bolted together. The shaft 2 which is provided with a shoulder 11 at the end dispose'd within the box 3, is terminated by a disc 12 situated in a recess formcd in the cover 9. The said disc and the shoulder 11 are journalled with modcrate friction and without play in the cover 9. Upon the disc 12 and integral therewith are disposed upon a circumference and with 120 spacing, three tapered nibs 13, 14 and 15. The latter are engaged in the slots 16 which have inclined walls and are tormed according to diameters in a second disc 17 which is also revoluble with moderat e friction and without play in a correspondng re'cess in the lower cover 10. The cross section of the slots 16 corresponds exactly to the taper of the said nhs.

The recesses in the covers 9 and containing the respective discs 12 and 17 are not Situated upon a common centre line, but are in the eccentric position by a quantity which is exactly equal to the radius of the circumference upon which the three tapered nibs are Situated. The disc 17 is mounted upon a shaft 18 which is journalled with moderate friction and without play in a bored-out portion of the cover 10 and .which terminates in a tapered portion 19 which is screwthreaded at the end. The steering lever l is fitted and also keyed at 20 upon the tapered portion 19, and a slotted nut screwed to the said screwthreaded part is Secured to the latter by a pin in order to maintain the lever 4 in position. A spring 21 disposed in a recess in the cover 10 coustantly urges the disc 17 and maintainsthe contact at all times between the slots 16 and the tapered nibs of the disc 19 e a For the sake of Simplicity, it will be understood in the following description that all the tapped parts engaging the screwthreaded portions are to be fitted with moderate friction and without play; The outer end of the lever 4 is provided with a screwthread which is'dsengaged at each. end and upon which is screwed a member 22 pro i I D have rotated through an angle Tlt'letl with an aperture and with a screwthreadetl shanl; 223; upon the etter is screwezl a tappeil portion which is t'orne( upon one end of the steel-ing har 5, the other end of si'tl har being' serewthreaded' in order to engage a tappetl meniher Figs. 10 to li At the onter end ot the letter is (lisposetl a screw threaded rocl eng-aging a tappe hole which is pe'pendienlar to th hole engagin' the end ot' the bar 5; the rod 26 is ?ecin-ed to a Fcrewthreaded tork 2? whieh is serewed to the end ot the lerer ti. this arrangeinent being shown in Fier 12, which is a section on the line C-C ot Figs. lt) and ll.

Before inounting the torl 97 upon the lever G, a like tork 28 is (llr poctl thereon, whose serewthreuled shanl i; serewed into a eonneeting meniher 20 iito whieh is ECt'tWCl the end ot the, eouplin ha The arrangenent ot the har S upon the other eonneeting lover 'i is sinilar except' thet the said har is not reailuhle upon the ineinher %tt-*similar to :D eonneding the &zune with the lCYCl' T.

The operation ot' the said speed re ln'tion hor (lepends upon La Hire's tllCOl'OHl;

It .is OlE'Cl'VOtl that according' to this theoren, when a eircninterence, whose (li-aneter is equal to the relius ot another circuniterence, is caus il to roll upon this lat'- ter, a given point upon the small circinnference will (leserihe a diameter of the second. Further, the sin-.ill oirennterenee will make two revolntiono before returning to the start-ing point. Inversely, it the small creunterenee is rotate l, while obliging a given point thereupon to proeeed upon a diameter ot the large eircuinterenee, this latter heing let't 'tree to more, the necessary result will he e rotat'ion ot the ,n'ge Cireun'terenee. ltu'ther, when the small cirenmterence nahes two reroluti,ns the large eircuinterenee will inal e one revolution.

The s peed-re'l a-tion hor: perta ning t the ssteering; arrangenient according to the intention; iii a direc application ot this reciproeal movement'. As ahere stated, the slia'tts ot the (Uses lil and lT are PlttC-Gt'lin the eecentrio position hy a qnantity equal to the radius o'l the eireuint'erenee eotnpriine the nibs l l, Il; and 15.

Supposing that: the nix are in the pesh tion shown in Flm. x Lit l 7, inwhich they are engaged in the Slots ;tt' it the shutt i] is; rotatecl in the direction of-the arrow 3, Fig. T. the nihs 13 and ll will aetuate the (lisc 17 whilst the nilj 15 will proeeetl through the diseugaged centre ot the Stlll (li e (Fig. S) in order to altain the position shown in Fig. t). [t the (lisa 19 iF; turned through an angle P, the (liszo 1-? will Continu- 2 ing the rotation ot the shalt 2 in the same direction, the (lerice will still he aetnateth since the nit '15 renains in its: slut anl tlunih 13 in tl e eorresponding Slot, whilst the nih 14-. is gradnally disen'aged froni the slot with w'hieli it co-operates.

lt Sltltll( he ohserred; that ii'respeeti\'el of the respective positions oi" the two di L least two ot' the nilis will he eng'agett ii.

'he said slots. l L

l etweeir the norenont ot the hai:: ttlltl thonorenent whieh i' rehiele wheelss. The i'ztio wl .i with the pres-'ont &teorine arrznrenzn s ahere mentioneth aint this: ra e( iee ai' a rule tor light \'t*l]ltfl`f-'. should it: prom neressrfi. the y may he inereaeed hy lenethening: t.

tltQtl lever and shortening the, aztnatin lover.` For example, the length ot tl e aetnating lever is one-halt the length ot' the aetuated lover; the total re-;luetion ratio hetween the hand wheel and the \"ehiele wheels is X L. 1( I) This particular point eoneerning the 50301"- ing arrangenent having heen properly set torth, the opera ing Conditions ot' the several Controls and the Special arrangeinent ot their connections are to he 'further tmtith'tt, i

lVhen the lover l: rotates with the (llrfi 17, it draws 'torwartl t'lo meniher whit'l in turn artuates` the hai- F hy means: ot' its apert'nre fl t. inamnneh ae the :mele l'rmwl in paee hy the leter l aml the har. .7 ra'ies in tln' ee &steering planes perpeiulienlar t each other` theirjunction, though righl, inust he eti'eotetl on the universal prineiple. This oonlition is nealizml ;t'on the I'vt that tirstly the (leYice Can ho rotatwl in the horizontal plane hy reason-ot: the rotation ot the apertnre. 22 upon the lover 1: sm ondly, the clerce can he rotat'ed iuthe vertical plane with respect) to tla` xtrenity the'eot hy reason of the rotation ol' the apertnre 22, thrdly, the deviee can l e rotatecl in the Vertical plane ot pnj tii t reason of the rotation ot the har i in the nenher 25.

,lt should he ohz-seri'etl that', the tlillt'tlltlhlfj ot rotation will in no wise attain tho -nplote` eircumterence SO that itkaie tal en to engage the eonpllng nenihers by ltl'' than one serewthread, the latter can never become unseiewed. To n'ove this point, it the ease of the steering ar 5 is eonsideml,

it is observed that the said har cannot rotate or become unscrewed from the coupling member 25 *since it is maintained hy the shank 23 of the apertured member 22, which latter is maintained approximately in the horizontal position by the lever 4. The

.coupling bar 8, which serves to connect the recprocal movement of the two wheels, is'

arranged in likemanner, and the member 29 is screwed upon the same screwthreaded portion of the lever 6 as the member 25.

The above-described connections are of an economical nature inasmuch as their construction requires only the formation of screwthreads, which is easily carr ied out. On the other hand, when in operation, even if the said connections are not protected, the screwthreads which are engaged will never be uncovered, since the longitudinal movement of an aperture upon its corresponding` screwthreaded portion will represent only the amplitude of an additional pitch, corresponding to a rotation of 180 So that dust or grit cannot enter upon the surfaces in contact,- and hence wear of the said surfaces will be diminished; the surfaces will be thus enabled to maintain their operation for a considerable time without play. It is to be further remarked that no pins are required for the maintenance of the said universal connections, and that the parts ot the said device cannot become disengaged when in operation. No accidents can therefore happen with the said ari-angement.

I claim:

In a steering arrangement for motor vehicles, the combination of a Shaft with a hand wheel, a speed reduction gear controlled by said steering shaft, and transmission means between the said speed reduction gear and the steering wheels of the vehicle, this speed reduction gear comprising a small disc keyed tothe steering shaft, tapered nibs arranged upon the said disc and spaced at regular intervals about a circumference, a

large disc adapted to be connected with the said transmission means, this large disc being movable axially and occupying an eccentric position relative to the first one and being provided with radial Slots of a trapezoidal section corresponding in number to that of the tapered nibs, the latter being adapted to enter and slide in these Slots, and means adapted to press the said discs the one against the other.

In testimony that I claim the `foregoing as my invention.

THODORE LAFITTE. 

